Top Circuits Page 137
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This circuit is the variable output switching regulator for general purpose applications. An LM105 positive regulator is used as the amplifier-reference for the switching regulator. Positive feedback to induce switching is obtained from the LM105 at pin 1....
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This is a circuit schematic diagram power amplifier, the power amplifier circuit diagram using the IC TLE2141C. This power amplifier is TLE2141C IC IC type Low noise, high voltage, high-slew-rate op-amps. Frequency response 30Hz to 20KHz-1dB. You can connect....
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The impedance of these current generators is essentially infinite for small currents and they are accurate so long as VIN is much greater than VOS and IO is much greater than I bias. The source use an FET to drive a bipolar output transistor. It is possible....
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The circuit a series of Dual Power Supply, where the symmetrical ± 15V supply for linear circuits. The same principle applies to supplies of non-symmetrical, such as 5. 0 V and-12V regulators for applications such as registers. To ensure start up LM340 over....
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This circuit is Wein Bridge Sine Wave Oscillator. The main problem in producing low distortion, constant amplitude sine wave to get the right loop gain amplifier. By using the 2N3069 JFET as variable resistor in the feedback loop voltage amplifier, this can....
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Simple circuit diagram is a schematic remote control, remote control where it consists of two parts of the transmitter and receiver. The first part is a transmitter, circuit diagrams for transmitter IC is controlled by the NE555. This system works by....
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This circuit is a mini bicycle bell. Mini bicycle bell is connected using the bell as a switch. If the button is pressed, an electric current flowing on the 9V voltage electronic circuit through the transistor Q1. because the speakers are connected to the....
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This circuit is a motion detection sensor, this circuit uses a light source and detector as a sensor infrared motion detector. Motion sensor using infrared LED and phototransistor. Because it uses light to the sensor sensitivity can be affected by....
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At certain times of the year I migrate a bit North of Southampton to an area where the the hams on VHF are grumbly and seem to be few and far between. Add to this that the local repeater only uses tone burst and that the QTH is right next to some noisy....
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Used Zener Diodes to derive the stabilized voltage for the Hartley oscillator (although I did find a couple of suitable voltage stabiliser valves (CV287) whilst sorting through a box of valves this morning). Whilst sniffing around in that box of valves....
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If you`ve never heard of geocaching, it`s kind of a grown-up treasure hunt you play everywhere in the world. GPS coordinates are given as clues and the players must find the cache box. There is usually a log book to write your name and a small toy or present....
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Making your own circuit boards can be a daunting challenge. You have to design a schematic, test it on a breadboard, design the board layout, and then after all of that, you still have to print and etch a board! Luckily, we have Fritzing. Fritzing is a free....
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The system described here is a four motor rotary wing aircraft with 3 inch propellers. The overall size of version one is about four inches. A 418MHz digital radio is used for communications and control and an onboard PIC17 microcontroller and L293DD mosfet....
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The first one I bought for US$ 3. It has an internal rectifier, and even after I dug it out of the epoxy, performance was still poor. The next two were given to me by the ever kind and helpful Francis Rutherford at the Regional Occupations Program and....
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This is a step by step guide to modifying the disposable camera flash unit that powers the Geiger tube in the last post. Geiger tube power supply hack using disposable camera flash unit Remove the flash tube and trigger transformer from the circuit board....
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How to make the hardware connections between the Raspberry Pi and the house wiring. Check out this post if you want a PCB that does the connections for you. In my house (and the vast majority of others) the thermostat wiring runs at 24V AC. There`s a live....
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We’d like to be able to use a PC to measure the temperature outside. Ideally this would be a serial connected device with a probe that could easily be placed outside. Google found us some, but there seem to be very complex and cost around $100! ..
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The circuit is designed to be fitted into a small box and then fitted into your backbox (the exact choice of position is yours). Only 3 wires are required - one for the battery +v, one for the supply +5 volts from the MPU board or power supply and a common....
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Be sure to use the correct 9-pin `D` type connector so the pins fit in the board. The two outer holes for mounting the 9-pin `D` type connector should be 3mm Dia. and the holes for the pins are 1. 2mm Dia. The PCB is also tailored for a PCB mounting 5-pin....
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By using light and sound to induce these brain states we are able to gain greater control and efficiency of brain usage. Furthermore, improvements in relaxation, memory, creativity, stress management, sleep disorders, and even ESP(!) can be had by utilizing....
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This page is going to describe the parts, schematic, softw1are, and some tips on using Infrared for object detection. The parts used are typically the same parts found in most consumer electronic remote controls, and are widely available. If you have an old....
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It has been designed as a panel meter and can be used in DC power supplies or anywhere else it is necessary to have an accurate indication of the voltage present. The circuit employs the ADC (Analogue to Digital Converter) I. C. CL7107 made by INTERSIL. This....
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The circuit diagram of the Lie Detector is shown above. It consists of three transistors (TR1 to TR3), a capacitor (C1), tw1o lights or LEDs (L1 & L2), five resistors (R1 to R5), and a variable resistor (VR1). This circuit is based on the fact that a....
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SW1 should be ganged to P1 to avoid abrupt voltage peaks on the "patient`s" body at switch-on, but a stand alone SPST switch works quite well, provided you remember to set P1 knob fully counter-clockwise at switch-on. Some commercial sets have four, six or....
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The game Tetris using a PIC16F84 running @ 12MHz. Tetris is an old Russian computer game where you should try to fit in block into a play-field, quite simple but really fun. In my version, the video signal is generated in softw1are. The only hardware used....
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This circuit uses a 1458 dual op-amp to form a radar detector. C1 is the detector of the radar signal. The first op-amp forms a current-to-voltage converter and the second op-amp buffers the output to drive the piezo transducer. R5 sets the switching....
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This article presents a simple FCD circuit that can be built by anyone with moderate electronics assembly expertise. In addition, the article covers the reasons why an FCD is needed, why this FCD is superior to other FCD designs, and the theory of operation.....
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The first circuit is a simple preamplifier showing the power arangements for conveying DC to the amplifier via the coaxial cable. The second circuit is a small modification so the antenna can still be used for transmitting. The actual preamplifier in this....
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The OPT301 is in a TO-99 8 lead package and has good sensitivity but a reduced bandwidth of 4kHz. The peak response is just into the Infra Red region at 750nm but its sensitivity in the visible red spectrum at 670nm is only a few percent down. The circuit is....
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This is a simple microphone preamplifer circuit which you can use betw1een your microphone and stereo amplifier. This circuit amplifier microphone suitable for use with normal home stereo amplifier line/CD/aux/tape inputs. This mic preamp can take both....
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This design was born of frustration with the mic preamp in my Sony R91. It clips at ridiculously low levels, basically it has 28mV of headroom to deal with an input that could be as high as 1800mV (depending on mic & volume), so this design attempts to cure....
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The loop can be any type of hookup wire, with a maximum resistance of about 90K. Using very thin wire (40AWG, for example) will make a very sensitive trip wire, but will shorten the distance it can be strung due to the high resistance...
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A dual axis solar tracker system circuit which is intended forautomaticallyadjusting the solarpanelface such that it stays perpendicular to the incident sun rays at all instants. throughout the day. However for this to happen whole set up involves many....
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This is a design circuit for low current relay circuit is designed to be used in battery operated electronic devices. Its operating current is in micro amperes ( µA). This is done by using a bistable relay and adding some components to force the relay to....
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This circuit is conventional Pierce type oscillator that uses a JFET. The circuit uses fundamental mode crystals. It has decent performance and reliability if we use a low noise JFET. This is the figure of the circuit. The feedback is controlled by the C1....
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This is a circuit that is used to menhidupkan LED with voltage 230Volt, 230Volt it so that the voltage must be lowered in accordance with the needs of the LED itself. To lower it even necessary circuit as below...
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This lead acid battery charger circuit is designed in response to a request from Mr. Devdas. C. His requirement was a circuit to charge two 12V/7AH lead acid batteries in series. Anyway he did not mentioned the no of cells per each 12V battery. The no of....
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The circuit for a powerful AM transmitter using ceramic resonator/filter of 3. 587 MHz is presented here. This circuit is based on transistor for the core operation of the circuit. Resonators/filters of other frequencies such as 5. 5 MHz, 7 MHz and 10. 7 MHz....
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This is design for charger circuit that is suitable for lead-acid battery, including flooded, gel, and AGM types. This circuit is simple design. This is the figure of the circuit. The automatic term means that this charger will stop charging automatically....
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This circuit will flash a white LED, on a supply from 2v to 6v and produce a very bright flash. The circuit takes about 2mA and old cells can be used. The two 100u electros in parallel produce a better flash when the supply is 6v...
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This is a design circuit for alarm. This circuit is for an anti- theft wireless alarm can be used with any vehicle having 6 to 12 volt DC supply system. The mini VHF FM radio-controlled, FM transmitter is fitted in the vehicle at night when it is parked in....
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If a circuit is to switch a mains voltage, a relay is a simple solution in cases where switching times are long and high currents are involved. However, at lower currents, and in particular where rapid switching is required, such as in sound-to-light....
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This is the simple freeze protector circuit diagram. It is also called timing circuit. It is just hobby project for beginners. When you need to operate automatically any device in the fixed time later after coming AC power supply, you can use this circuit.....
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The TV transmitter circuit given here uses UK standard 1 FM modulation for sound and PAL for video modulation. The audio signal to be modulated is pre-amplified using the transistor Q1 and associated components. The transistor Q2 has two jobs: production of....
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This is a design circuit for an electrostatic transducer for ultrasonic measurement circuit. This circuit uses the LM1812 ultrasonic transceiver. Transducer x1 and LM1812 will transmit a burst of oscillations. Then the return echo is listened by using X1.....
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If you ever wanted to integrate RFID functionality into your project, this small tutorial might help you accomplish that. I used the RDM630 module from seeedstudio in its UART version. It comes on a small board with presoldered connectors which fits....
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The next board I want to show you is the ADJD-S371 Color Light Sensor Evaluation Board from sparkfun. It emits light and analyses the reflected color spectrum. The board can be controlled via I2C. The sleep and xclk pins were not used in this example. I....
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I`ve been looking around for a mains (220-240VAC) power monitoring circuit that I might be able to interface with an Arduino. There is of course the OpenEnergyMonitor solution, but they seem to use a transformer to isolate and measure the mains voltage. The....
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Taking inspiration from the good folks at Nanode and an Instructable I saw recently, I`ve come up with another AVR based Ethernet board that can be programmed and used like an Arduino. It`s a simple design based on the ATMega and Microchip`s ENC28J60....
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The PWM controlled modified sine wave inverter circuit presented here uses just a single 4093 for the specified functions. The IC consists of four NAND gates, out of which two are wired up as oscillators while the remaining two as buffers. The oscillators....
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IC TDA7052 is a mono output amplifier in 8-comng Head DI package (DIP). The device is designed primarily for battery-operated portable audio circuits. Features include TDA 7052, no external components needed, no switch-on or switch-off button sounds great....
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Connection and wiring between each parts and component of exterior lights system of the vehicle such as the fusible link, junction block, tail light relay, cruise control, stop light switch, relay box, column switch, rear combination light, front combination....
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This is the circuit of waveform generator. Waveform generator is very useful in electronic experiment and design. This circuit is generates sine wave oscillation, but actually we can modify the circuit to generate triangle or square wave function. This is....
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On Halloween night, I reguarly have periods of 5, 10, and even 15 minutes where no ToTs are around. It seemed kind of silly to me to have the fogger spewing fog during such breaks by using a standard fogger timer. Instead, I decided to build my own custom....
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The spider prop is fairly simple in terms of mechanical setup. Where it gets somewhat complicated is in the electronics setup. It is based around a stepper motor. By their very nature, stepper motors are non-trivial to control. By that, I mean that you can`t....
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The fridge cut in and the lights got brighter. I thought we were imagining it but we watched for several cycles, and it kept happening. Then we tried turning on the microwave, and the lights got dimmer. But the fridge definitely made it get brighter. I think....
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By sufficiently lowering output impedence of a circuit and supplying enough current to drive cables, it does not suffer the same problems as passive designs. As such, it seems to solve the many of the problems inherent in both active and passive preamps....
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This is a single zone alarm - with automatic exit, entry and siren cut-off timers. It will accommodate all the usual types of normally-closed input devices - such as magnetic-reed contacts - foil tape - PIRs etc. I`ve used a 12-volt supply in the drawing -....
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The circuit provided in this article shows you a simple way of building a useful liitle inverter thats easy to build and yet provides the features of a pure sine wave inverter. The circuit can be easily modified for getting higher outputs. The input stage....
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C2 can be chosen for the degree of smoothness as its value is effectively multiplied by the combined gains of Q1/Q2, if 100 µF is chosen for C2, assuming minimum hef for Q1 and Q2,..
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Barrier measurement of distance method applied is with measuring strength of bound signal. Reflection wave is catch with an acceptor transducer. Acceptor transducer releases sine signal which the amplitude depended from barrier distance with transducer.....
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This is a simple design for Voltage Regulator Circuit using pass transistor. The design has built by LM317T. The LM317T output current can be increased by using an additional power transistor to share a portion of the total current. The amount of current....
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This is an article written by a one of my readers, Yash Tambi, Core Committee Member, roboVITics. Do read this post and pitch in your comments below regarding this. Thanks! RF controlled bots are the most simple of their kind. All you need are a few ICs,....
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SMPS design and analysis requires an understanding of many different areas of study. This article is intended to help the reader become familiar with the several different SMPS topologies, and their general performance characteristics. The major information....
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Hello all, I ran across this schematic for a watch timer in a hobby electronics book. Anyone built something like this before? My knowledge of electronics is somewhat limited. Here is the description: ""This circuit adapts a frequency counter to measure....
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The Sparkfun Solid State Relay (SSR) Breakout Board is shown below. An SSR works like a relay but is built using semiconductors for switching. It will run off of mbed`s VU 5V supply and works with any mbed digital output pin. The schematic is shown below for....
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This setup allows you to allocate the pins of an mbed for a specified interface without having to recompile the code. It uses a PS/2 Keyboard as an input device and an LCD as an output device. It can take commands and interpret them according to predefined....
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One problem this causes is that the lovely USB port that I have been using to communicate with hyperterminal will no longer be available. So I need an alternative. This lead me to the FT232RL chip. I picked this mainly because it is already in Eagle and....